The present invention relates to the formulation of mineral fortified beverage products containing sodium hexametaphosphate as a preservative.
Beverage products frequently utilize sodium hexametaphosphate (SHMP) as a preservative. It is important to have an effective preservative in beverage products since such products tend to require a relatively long shelf life from manufacture to retail outlet to drinking by the consumer. SHMP, although often referred to as a hexametaphosphate, technically is a polyphosphate and a powerful chelating agent. The SHMP functions as a preservative by extracting divalent metallic ions from microbial enzymatic systems. This prevents calcium, iron and magnesium utilization by microorganisms; this interrupts their physiology, resulting in the organisms' death.
While it is desirable to provide vitamin or mineral fortification in some beverage products, particularly beverage products aimed at children, such supplementation can present formulation difficulties in beverages with chelating preservatives. For example, if a beverage product is to be fortified with vitamin D3, federal regulations require that the beverage also be fortified with calcium. Calcium, however, can deactivate the SHMP preservative, thereby significantly decreasing the shelf-life of the product. Thus, the beverage must be formulated such that the calcium does not deactivate the SHMP or otherwise impede its function, the calcium must also be bio-available, not produce unacceptable tastes or colors, must not settle out of the product, must be able to be processed on a large scale, and not add significant cost to the beverage product. Thus, the goal in formulating beverages, and particularly the goal in the present invention, is to develop a form of calcium which is an effective dietary supplement (i.e., bio-available), but which does not deactivate the SHMP preservative, and which is safe, cost-effective and easy to use in a beverage product. In addition, the calcium material utilized in the beverage cannot impart off-flavors or bad mouthfeel to the product and must be easy to incorporate within the product. That is what the present invention accomplishes.
Specifically, SHMP is a powerful chelating agent. It functions as a preservative by extraction of divalent metallic ions (e.g., calcium, iron, magnesium) from microbial enzymatic systems. The extracted metals are no longer available to the microbes and so the microbes enter a stationary phase and, finally, a death phase.
It has been estimated to require 0.24 g of a polyphosphate (e.g., SHMP) to kill 1×103 CFU's (colony-forming units) of microorganisms. The level of calcium contained in 1×103 CFU's of microorganisms is estimated to be approximately 2.6×10−8 g. The addition of 100 mg of calcium to a beverage containing SHMP will inactivate the SHMP and support the growth of 3.85×109 CFU's.
The question arises as to how best to add calcium to a beverage containing SHMP as required by 21 CFR 172.380, in order to supplement with Vitamin D. In addition, the calcium must not deactivate the SHMP or impede its function, the calcium must be bio-available, produce no unacceptable taste or color, must not precipitate out and be able to be processed on a large scale.
The present invention provides a calcium polyphosphate product (e.g., calcium hexametaphosphate) which can be used to provide a bio-available source of calcium to a beverage product without deactivating the SHMP preservative in that beverage product. The present application also describes the formation of calcium hexametaphosphate particles, particularly coated particles, and also describes methods of making the calcium polyphosphate-calcium hexametaphosphate material. Finally, the present invention teaches how to formulate the calcium polyphosphate so as to minimize any off-tastes.